Pipes and other such conduits are commonly used in many applications for conveying fluid materials between locations. In order to ensure safety, it is common to conduct integrity tests on pipes to identify any cracks or other such openings through which the fluid being conveyed may leak. These cracks may result from defective welds on the pipe or from a defect in the tube manufacturing process. Pipe integrity testing is particularly important in situations where the pipe is used to convey flammable or toxic substances or when the pipe is conveying fluids under high pressure.
Various apparatus and methods are known in the art for testing pipes. In some of these known methods, a pipe section is simply filled with a typically incompressible fluid and pressurized while monitoring the pressure within the pipe. Any pressure drop is indicative of a leak in the pipe wall. Although effective, these known methods are inefficient since they require the entire volume of the pipe to be filled and pressurized, which is problematic when the pipe volume is large due to either a large diameter or a long length.
The prior art provides various types of pipe testing devices such as those taught in the following U.S. Pat. Nos. 6,463,791; 6,131,441; and, 5,844,127 (all of which share a common inventor with the present invention). Although these devices have proven effective in conducting tests on sections of pipe, there exists a need for an apparatus that efficiently tests lengths of pipe. Such a device is taught in U.S. Pat. No. 4,067,228. This reference provides an apparatus having a mandrel for insertion within a pipe segment to create an annular space between the inner pipe wall and the outer surface of the mandrel. In order to conduct the integrity test, a small volume of fluid is injected in the annular space and pressurized. Although providing an efficient test method, the apparatus of this reference is quite complicated and difficult to move from one location to another. Further, this reference does not provide a means of testing curved sections of pipe.
In some cases, the pipe to be tested may be formed of two or more segments that are welded together. In such cases, the segments or sections of the pipe are first joined, typically by welding, on one apparatus and then moved to another apparatus for the testing step. As will be understood, this two step process results in increased equipment and time costs.
Thus, a need exists for a more efficient apparatus for testing the integrity of sections of pipes. In addition, a need exists for more efficiently joining and testing a pipe formed from two or more segments.